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        <h2>
          <span class="refentrytitle">active</span>
        </h2>
        <p>active — 
      Returns the number of active instances of an instrument.
    </p>
      </div>
      <div class="refsect1">
        <a id="idp89052608"></a>
        <h2>Description</h2>
        <p>
      Returns the number of active instances of an instrument.
    </p>
      </div>
      <div class="refsect1">
        <a id="idp89053984"></a>
        <h2>Syntax</h2>
        <pre class="synopsis">ir <span class="command"><strong>active</strong></span> insnum [,iopt]</pre>
        <pre class="synopsis">ir <span class="command"><strong>active</strong></span> Sinsname [,iopt]</pre>
        <pre class="synopsis">kres <span class="command"><strong>active</strong></span> kinsnum [,iopt]</pre>
      </div>
      <div class="refsect1">
        <a id="idp89125296"></a>
        <h2>Initialization</h2>
        <p>
      <span class="emphasis"><em>insnum</em></span> -- number or string name of the instrument to be reported
    </p>
        <p>
      <span class="emphasis"><em>Sinsname</em></span> -- instrument name
    </p>
        <p>
      <span class="emphasis"><em>iopt</em></span> -- select currently active (zero, default),
      or all every active (non zero)
    </p>
      </div>
      <div class="refsect1">
        <a id="idp89128912"></a>
        <h2>Performance</h2>
        <p>
      <span class="emphasis"><em>kinsnum</em></span> -- number or string name of the instrument to be reported
    </p>
        <p>
      <span class="emphasis"><em>active</em></span> returns the number of active
      instances of instrument number
      <span class="emphasis"><em>insnum/kinsnum</em></span> (or named instrument
      <span class="emphasis"><em>Sinsname</em></span>). As of Csound 4.17 the output is
      updated at k-rate (if input arg is k-rate), to allow running
      count of instr instances. 
    </p>
        <p>
      As of Csound 5.17 if the instrument number is given as zero then
      all instruments are counted.
    </p>
      </div>
      <div class="refsect1">
        <a id="idp89133376"></a>
        <h2>Examples</h2>
        <p>
      Here is a simple example of the active opcode. It uses the file
      <a class="ulink" href="examples/active.csd" target="_top"><em class="citetitle">active.csd</em></a>. 

      </p>
        <div class="example">
          <a id="idp89135360"></a>
          <p class="title">
            <strong>Example 40. Simple example of the active opcode.</strong>
          </p>
          <div class="example-contents">
            <p>
          See the sections <a class="link" href="UsingRealTime.html" title="Real-Time Audio"><em class="citetitle">Real-time
          Audio</em></a> and <a class="link" href="CommandFlags.html" title="Csound command line"><em class="citetitle">Command Line
          Flags</em></a> for more information on using command
          line flags.
        </p>
            <pre class="programlisting">
<span class="csdtag">&lt;CsoundSynthesizer&gt;</span>
<span class="csdtag">&lt;CsOptions&gt;</span>
<span class="comment">; Select audio/midi flags here according to platform</span>
<span class="comment">; Audio out   Audio in</span>
-odac           -iadc    <span class="comment">;;;RT audio I/O</span>
<span class="comment">; For Non-realtime ouput leave only the line below:</span>
<span class="comment">; -o active.wav -W ;;; for file output any platform</span>
<span class="csdtag">&lt;/CsOptions&gt;</span>
<span class="csdtag">&lt;CsInstruments&gt;</span>

<span class="comment">; Initialize the global variables.</span>
<span class="ohdr">sr</span> <span class="op">=</span> 44100
<span class="ohdr">kr</span> <span class="op">=</span> 4410
<span class="ohdr">ksmps</span> <span class="op">=</span> 10
<span class="ohdr">nchnls</span> <span class="op">=</span> 1

<span class="comment">; Instrument #1 - a noisy waveform.</span>
<span class="oblock">instr</span> 1
  <span class="comment">; Generate a really noisy waveform.</span>
  anoisy <span class="opc">rand</span> 44100
  <span class="comment">; Turn down its amplitude.</span>
  aoutput <span class="opc">gain</span> anoisy, 2500
  <span class="comment">; Send it to the output.</span>
  <span class="opc">out</span> aoutput
<span class="oblock">endin</span>

<span class="comment">; Instrument #2 - counts active instruments.</span>
<span class="oblock">instr</span> 2
  <span class="comment">; Count the active instances of Instrument #1.</span>
  icount <span class="opc">active</span> 1
  <span class="comment">; Print the number of active instances.</span>
  <span class="opc">print</span> icount
<span class="oblock">endin</span>


<span class="csdtag">&lt;/CsInstruments&gt;</span>
<span class="csdtag">&lt;CsScore&gt;</span>

<span class="comment">; Start the first instance of Instrument #1 at 0:00 seconds.</span>
<span class="stamnt">i</span> 1 0.0 3.0

<span class="comment">; Start the second instance of Instrument #1 at 0:015 seconds.</span>
<span class="stamnt">i</span> 1 1.5 1.5

<span class="comment">; Play Instrument #2 at 0:01 seconds, when we have only </span>
<span class="comment">; one active instance of Instrument #1.</span>
<span class="stamnt">i</span> 2 1.0 0.1

<span class="comment">; Play Instrument #2 at 0:02 seconds, when we have </span>
<span class="comment">; two active instances of Instrument #1.</span>
<span class="stamnt">i</span> 2 2.0 0.1
<span class="stamnt">e</span>


<span class="csdtag">&lt;/CsScore&gt;</span>
<span class="csdtag">&lt;/CsoundSynthesizer&gt;</span>
</pre>
          </div>
        </div>
        <p><br class="example-break" />

      Its output should include lines like this:
      </p>
        <pre class="screen">
instr 2:  icount = 1.000
instr 2:  icount = 2.000
      </pre>
        <p>
    </p>
        <p>
      Here is a more advanced example of the active opcode. It displays the results of the active opcode at k-rate instead of i-rate. It uses the file <a class="ulink" href="examples/active_k.csd" target="_top"><em class="citetitle">active_k.csd</em></a>.

      </p>
        <div class="example">
          <a id="idp89141808"></a>
          <p class="title">
            <strong>Example 41. Example of the active opcode at k-rate.</strong>
          </p>
          <div class="example-contents">
            <pre class="programlisting">
<span class="csdtag">&lt;CsoundSynthesizer&gt;</span>
<span class="csdtag">&lt;CsOptions&gt;</span>
<span class="comment">; Select audio/midi flags here according to platform</span>
<span class="comment">; Audio out   Audio in</span>
-odac           -iadc    <span class="comment">;;;RT audio I/O</span>
<span class="comment">; For Non-realtime ouput leave only the line below:</span>
<span class="comment">; -o active_k.wav -W ;;; for file output any platform</span>
<span class="csdtag">&lt;/CsOptions&gt;</span>
<span class="csdtag">&lt;CsInstruments&gt;</span>

<span class="comment">; Initialize the global variables.</span>
<span class="ohdr">sr</span> <span class="op">=</span> 44100
<span class="ohdr">kr</span> <span class="op">=</span> 4410
<span class="ohdr">ksmps</span> <span class="op">=</span> 10
<span class="ohdr">nchnls</span> <span class="op">=</span> 1

<span class="comment">; Instrument #1 - a noisy waveform.</span>
<span class="oblock">instr</span> 1
  <span class="comment">; Generate a really noisy waveform.</span>
  anoisy <span class="opc">rand</span> 44100
  <span class="comment">; Turn down its amplitude.</span>
  aoutput <span class="opc">gain</span> anoisy, 2500
  <span class="comment">; Send it to the output.</span>
  <span class="opc">out</span> aoutput
<span class="oblock">endin</span>

<span class="comment">; Instrument #2 - counts active instruments at k-rate.</span>
<span class="oblock">instr</span> 2
  <span class="comment">; Count the active instances of Instrument #1.</span>
  kcount <span class="opc">active</span> 1
  <span class="comment">; Print the number of active instances.</span>
  <span class="opc">printk2</span> kcount
<span class="oblock">endin</span>


<span class="csdtag">&lt;/CsInstruments&gt;</span>
<span class="csdtag">&lt;CsScore&gt;</span>

<span class="comment">; Start the first instance of Instrument #1 at 0:00 seconds.</span>
<span class="stamnt">i</span> 1 0.0 3.0

<span class="comment">; Start the second instance of Instrument #1 at 0:015 seconds.</span>
<span class="stamnt">i</span> 1 1.5 1.5

<span class="comment">; Play Instrument #2 at 0:01 seconds, when we have only </span>
<span class="comment">; one active instance of Instrument #1.</span>
<span class="stamnt">i</span> 2 1.0 0.1

<span class="comment">; Play Instrument #2 at 0:02 seconds, when we have </span>
<span class="comment">; two active instances of Instrument #1.</span>
<span class="stamnt">i</span> 2 2.0 0.1
<span class="stamnt">e</span>


<span class="csdtag">&lt;/CsScore&gt;</span>
<span class="csdtag">&lt;/CsoundSynthesizer&gt;</span>
</pre>
          </div>
        </div>
        <p><br class="example-break" />

      Its output should include lines like:
      </p>
        <pre class="screen">
 i2     1.00000
 i2     2.00000
      </pre>
        <p>
    </p>
        <p>
      Here is another example of the active opcode, using the number of instances to calculate gain. It uses the file <a class="ulink" href="examples/active_scale.csd" target="_top"><em class="citetitle">active_scale.csd</em></a>.
      </p>
        <div class="example">
          <a id="idp89145616"></a>
          <p class="title">
            <strong>Example 42. Example of the active opcode at k-rate.</strong>
          </p>
          <div class="example-contents">
            <pre class="programlisting">
<span class="csdtag">&lt;CsoundSynthesizer&gt;</span>
<span class="csdtag">&lt;CsOptions&gt;</span>
<span class="comment">; Select audio/midi flags here according to platform</span>
<span class="comment">; Audio out   Audio in    No messages</span>
-odac             -d     <span class="comment">;;;RT audio I/O</span>
<span class="comment">; For Non-realtime ouput leave only the line below:</span>
<span class="comment">; -o atone.wav -W ;;; for file output any platform</span>
<span class="csdtag">&lt;/CsOptions&gt;</span>
<span class="csdtag">&lt;CsInstruments&gt;</span>

<span class="ohdr">sr</span><span class="op">=</span> 44100
<span class="ohdr">ksmps</span> <span class="op">=</span> 64
<span class="ohdr">nchnls</span> <span class="op">=</span> 1
<span class="ohdr">0dbfs</span> <span class="op">=</span> 1

<span class="comment">;by Victor Lazzarini 2008</span>

<span class="oblock">instr</span> 1
kscal <span class="opc">active</span>  1
kamp <span class="opc">port</span>   1<span class="op">/</span>kscal, 0.01
asig  <span class="opc">oscili</span>  kamp, p4, 1
kenv <span class="opc">linseg</span> 0, 0.1,1,p3<span class="op">-</span>0.2,1,0.1, 0

        <span class="opc">out</span> asig<span class="op">*</span>kenv
<span class="oblock">endin</span>

<span class="csdtag">&lt;/CsInstruments&gt;</span>
<span class="csdtag">&lt;CsScore&gt;</span>
<span class="stamnt">f</span>1 0 16384 10 1

<span class="stamnt">i</span>1 0 10 440
<span class="stamnt">i</span>1 1 3  220
<span class="stamnt">i</span>1 2 5  350
<span class="stamnt">i</span>1 4 3  700
<span class="stamnt">e</span>
<span class="csdtag">&lt;/CsScore&gt;</span>
<span class="csdtag">&lt;/CsoundSynthesizer&gt;</span>
</pre>
          </div>
        </div>
        <p><br class="example-break" />
    </p>
      </div>
      <div class="refsect1">
        <a id="idp89147440"></a>
        <h2>Credits</h2>
        <p>
      </p>
        <table border="0" summary="Simple list" class="simplelist">
          <tr>
            <td>Author: John ffitch</td>
          </tr>
          <tr>
            <td>University of Bath/Codemist Ltd.</td>
          </tr>
          <tr>
            <td>Bath, UK</td>
          </tr>
          <tr>
            <td>July, 1999</td>
          </tr>
        </table>
        <p>
    </p>
        <p>Examples written by Kevin Conder.</p>
        <p>New in Csound version 3.57; named instruments added version 5.13</p>
        <p>Option for all ever active new in 5.13</p>
        <p>Count of all instruments new in 5.17</p>
      </div>
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